Boers 3.2 Homework he two exercises to check Skills MyMath Lab First complete the My MathLab homework online. Then work the two exercise your understanding. 1. for each pair of variables, determine if you expect a positive or negative con a. Salary and years of education 1. Unemployment rates and years of education 2. Does the following scatterplot indicate a linear trend in the data? If so, is the correla- tion positive or negative? 5 10 15 Concepts and Applications Complete the problems to practice applying the skills and concepts learned in the section 3. In this section, we saw a relationship between armspans and height. There are other linear relationships between body measurements. One such relationship is between the circumference of a wrist and the circumference of a neck. Wrap your hand around your wrist to get a sense of the circumference. The distance around your wrist is approximately the same as the circumference of the circle created with your thumb and middle finger. Now take your hands and wrap them around your neck. For many people, the circumference of their neck is approximately twice the circum- ference of their wrist. The following table lists wrist and neck circumferences for a group of college students. Wrist Circumference 5.5 6 6 6.5 7 7 7.5 8 8.5 9 1013 12.5 12 Neck Circumference (in.) 13.5 14 14 13 1821 309 32 WHATS TRENDING: CORRELATION e plo. Graphteck circumference versus wris o r h b. Graph the trenand wc represe b. Graph the trendline NC = 2.4WC - 2.8 on the scatterplot. NC represents neck circumference and WC represents wrist circumference. The trendline equation illustrates that neck circumference is approximately twice wrist circumference. C. Use the equation of the trendline to estimate the neck circumference in inches for someone whose wrist circumference is 6.25 inches. d. Find the residual for the predicted neck circumference from partc if the actual neck circumference is 12.5 inches. Interpret the value. 4. A linear model describes the relationship between the weight in pounds and the age in months for Great Dane puppies: Weight = 16.25(age in months) - 9.5. The model was created by using weights for puppies aged 2 to 6 months. a. Use the model to estimate the weight of a puppy at 2 weeks (half a month). 1 year, and 5 years. b. Does the model make sense for ages outside of 2 to 6 months? Why? of the Since Company Sales Predicted (Residual Residual 1.500 3 2 .100 5 1,800 .000 6 3 8 3,200 ollects the b. A student keeps track of how long it takes her to write her signature. She collect data in one sitting so that she can see if there is a change in her writing rate over writing rate over time. She wants to know if it takes her a lonper time due to fatigue or a shorter time repetition. Her data are given in the table. Number of Signatures Time (seconds) 4.42 8.66 2 3 13.51 16.26 23.6 28.11 30.17 32.56 33.68 35.87 10 When using Excel to find the equation of the trendline, she has an option for the Type of model. She chooses a linear model but notices that it doesn't seem to model the pattern closely. Next, she chooses polynomial models of different degrees to see how closely they fit the points. Each graph and its equation follow. Use each equation to predict how long it will take to write 7 signatures. Then find the residual for each prediction. 3.2 WHAT'S TRENDING: CORREU Time of Signatures Time Second Number of signatures y = 3.6344x + 2.6947 Time of Signatures Time (seconds) 10 Number of signatures y = -0.2492x + 6.3753x - 2.787 Time of Signatures Time (seconds) 8 10 Number of signatures y = -0.0352x + 0.3324x + 3.6928x + 0.2373 7. Looking Forward, Looking Back Simplify. -9 + 7 3-1-5 Boers 3.2 Homework he two exercises to check Skills MyMath Lab First complete the My MathLab homework online. Then work the two exercise your understanding. 1. for each pair of variables, determine if you expect a positive or negative con a. Salary and years of education 1. Unemployment rates and years of education 2. Does the following scatterplot indicate a linear trend in the data? If so, is the correla- tion positive or negative? 5 10 15 Concepts and Applications Complete the problems to practice applying the skills and concepts learned in the section 3. In this section, we saw a relationship between armspans and height. There are other linear relationships between body measurements. One such relationship is between the circumference of a wrist and the circumference of a neck. Wrap your hand around your wrist to get a sense of the circumference. The distance around your wrist is approximately the same as the circumference of the circle created with your thumb and middle finger. Now take your hands and wrap them around your neck. For many people, the circumference of their neck is approximately twice the circum- ference of their wrist. The following table lists wrist and neck circumferences for a group of college students. Wrist Circumference 5.5 6 6 6.5 7 7 7.5 8 8.5 9 1013 12.5 12 Neck Circumference (in.) 13.5 14 14 13 1821 309 32 WHATS TRENDING: CORRELATION e plo. Graphteck circumference versus wris o r h b. Graph the trenand wc represe b. Graph the trendline NC = 2.4WC - 2.8 on the scatterplot. NC represents neck circumference and WC represents wrist circumference. The trendline equation illustrates that neck circumference is approximately twice wrist circumference. C. Use the equation of the trendline to estimate the neck circumference in inches for someone whose wrist circumference is 6.25 inches. d. Find the residual for the predicted neck circumference from partc if the actual neck circumference is 12.5 inches. Interpret the value. 4. A linear model describes the relationship between the weight in pounds and the age in months for Great Dane puppies: Weight = 16.25(age in months) - 9.5. The model was created by using weights for puppies aged 2 to 6 months. a. Use the model to estimate the weight of a puppy at 2 weeks (half a month). 1 year, and 5 years. b. Does the model make sense for ages outside of 2 to 6 months? Why? of the Since Company Sales Predicted (Residual Residual 1.500 3 2 .100 5 1,800 .000 6 3 8 3,200 ollects the b. A student keeps track of how long it takes her to write her signature. She collect data in one sitting so that she can see if there is a change in her writing rate over writing rate over time. She wants to know if it takes her a lonper time due to fatigue or a shorter time repetition. Her data are given in the table. Number of Signatures Time (seconds) 4.42 8.66 2 3 13.51 16.26 23.6 28.11 30.17 32.56 33.68 35.87 10 When using Excel to find the equation of the trendline, she has an option for the Type of model. She chooses a linear model but notices that it doesn't seem to model the pattern closely. Next, she chooses polynomial models of different degrees to see how closely they fit the points. Each graph and its equation follow. Use each equation to predict how long it will take to write 7 signatures. Then find the residual for each prediction. 3.2 WHAT'S TRENDING: CORREU Time of Signatures Time Second Number of signatures y = 3.6344x + 2.6947 Time of Signatures Time (seconds) 10 Number of signatures y = -0.2492x + 6.3753x - 2.787 Time of Signatures Time (seconds) 8 10 Number of signatures y = -0.0352x + 0.3324x + 3.6928x + 0.2373 7. Looking Forward, Looking Back Simplify. -9 + 7 3-1-5